Who can the 2nd Mass trust, and who's marked for death, on Falling Skies?

We're halfway through season two of Falling Skies, TNT's show about the last remnants of humanity in the wake of an alien invasion. And the cast and crew assembled at Comic Con for a panel moderated by 2nd Watch host Wil Wheaton. The Second Mass is ever vigilant against the threat of aliens — but they weren't on guard against revealing a few spoilers for seasons two and three...

Karen is back!
We saw a short clip: Hal and Maggie come across a group of Harnessed children, covered in leaves. As Hal and Maggie sift for survivors amongst the dead, they find a very alive Karen in this clip from tomorrow evening's episode, "Homecoming." Karen will be rejoining the Second Mass, but can they trust her?

Where is Charleston?
Showrunner Remi Aubuchon narrowed down exactly which Charleston the 2nd Mass is marching toward — the city of Charleston, South Carolina. Discussion on the panel turned toward Tom's vision of Charleston - a place where some form of government exists, a government this former history professor can take a part in shaping. Once the group arrives in Charleston, they will meet a character deeply embedded in Tom's past — played by Terry O'Quinn.

Taking control of alien technology and a major character death
The subject of the 2nd Mass absconding alien technology came up during the panel, with Remi confirming that the 2nd Mass will be making use of some form of alien weaponry this season, but with no hint as to whether they will be controlling Mechs or not. The panel ended with hints that a major character will die at the end of season two, plus confirmation that season three is already greenlit by TNT.

Top image from TNT.